A vehicle airbag assembly typically comprises a reaction device and an airbag which is coupled to the reaction device. The reaction device is commonly adapted to be mounted to a structural part of a vehicle. For example, a passenger-side airbag is usually designed to be incorporated into the dashboard or instrument panel of a vehicle. One common form of a reaction device is a "reaction can" or, in other words, a wall structure forming a container which at least partially encloses the airbag.
The airbag includes an inflatable bag which is made of a suitable flexible fabric, such as nylon, and which includes a mouth defining a fluid inlet. The bag is adapted to be inflated to a desired configuration. If the bag was to be used in a passenger-side airbag assembly, it would probably be designed to be inflated into a generally cylindrical or drum-like shape.
An airbag assembly additionally typically includes an inflator and a cover which are also coupled to the reaction device. The inflator will usually comprise a housing enclosing a source of inflation fluid. The cover will usually be designed to separate into segments during deployment of the airbag.
When mounted to a vehicle, an airbag assembly operates to deploy the airbag at the onset of a vehicle collision. Specifically, at the onset of a collision, the inflator supplies inflation fluid to the inflatable bag. This supply of inflation fluid expands the bag to sequentially (although almost instantaneously) create an opening in the cover, force the bag through the opening into the occupant compartment, and fully inflate the bag to cushion an occupant against impact with a structural part of the vehicle.
As was indicated above, the airbag is typically coupled to the reaction device. In designing the airbag assembly of the present invention, applicants appreciated that this coupling could be accomplished by inserting suitable fasteners, such as rivets, through apertures in the mouth of the inflatable bag and aligned apertures in the reaction device. However, applicants also appreciated that, while this coupling process has proven to be effective, it frequently requires preliminary alignment procedures. More specifically, the airbag and/or the reaction device must often be manually manipulated and visually inspected during the preliminary stages of the coupling process to ensure that the apertures in the bag's mouth are properly aligned with the apertures in the reaction device. Thus, in designing the airbag assembly of the present invention, applicants wanted to use this effective method of coupling the airbag to the reaction device but also wanted to eliminate the need for preliminary alignment procedures.
In designing the airbag assembly of the present invention, applicants additionally wanted to incorporate a separate retainer, such as a frame-shaped component, into the airbag assembly. Applicants appreciated that such a retainer could be provided with apertures which were arranged to align with the apertures in the bag's mouth and with the apertures in the reaction device. In this manner, suitable fasteners, such as rivets, could be inserted through the aligned apertures in the reaction device, the bag's mouth, and the retainer to couple the airbag and the retainer effectively to the reaction device. Applicants also appreciated, however, that the introduction of a retainer could undesirably further complicate the preliminary alignment procedures of the coupling process.
Accordingly, an object of the present invention is to provide structures and techniques for effectively coupling an airbag and a retainer to a reaction device while at the same time eliminating the need for preliminary alignment procedures. This objective is accomplished by providing the airbag, the retainer, and the reaction device with mating members which, when appropriately mated or engaged, insure that the relevant coupling components (rivet-receiving apertures in the preferred embodiment) are properly aligned.
More particularly, the present invention provides a method of forming an airbag assembly comprising the steps of providing an airbag, providing a retainer, and providing a reaction device. The airbag includes an inflatable bag and airbag mating members which are attached to, and extend away from, the mouth of the inflatable bag. Preferably, the airbag mating members are part of a mating device which is incorporated into the bag's mouth. The retainer includes a base member and retainer mating members which are attached to, and extend away from, the base member. The retainer mating members are complementarily configured to mate with the airbag mating members.
In forming the airbag assembly, the airbag is joined to the retainer to form an airbag/retainer subassembly. Specifically, the airbag mating members are mated with the retainer mating members, thereby joining the airbag to the retainer in a predetermined alignment. In this predetermined alignment, the relevant coupling components of the airbag and the retainer (i.e., rivet-receiving apertures) are properly aligned. Thus, the mating of the airbag mating members with the retainer mating members simultaneously aligns the relevant coupling components of the airbag and the retainer so that preliminary alignment procedures are not necessary.
The airbag/retainer subassembly is then positioned in a predetermined orientation relative to the reaction device and thereafter coupled to the reaction device. In this predetermined orientation, the relevant coupling components of the reaction device (i.e., rivet-receiving apertures) are properly aligned with the relevant coupling components of the airbag and the retainer (i.e., already aligned rivet-receiving apertures). The reaction device preferably includes a cradle configured to engage the airbag/retainer subassembly and to align the airbag/retainer subassembly in the predetermined orientation. In this manner, the engagement of the airbag/retainer subassembly with the cradle simultaneously aligns the relevant coupling components so that preliminary alignment procedures are not necessary.
The reaction device may comprise a "reaction can" or, in other words, comprise a wall structure forming a container and defining a front opening. If the airbag assembly of the present invention includes such a reaction device, the positioning of the airbag/retainer subassembly may include inserting it through the front opening into the container. If the reaction device includes a cradle, the cradle would be preferably formed in one piece with the wall structure.
The method of the present invention may be used in conjunction with suitable fasteners, such as rivets, to couple the airbag and the retainer effectively to the reaction device while at the same time eliminating the need for preliminary alignment procedures. For example, the inflatable bag could be provided with apertures which are disposed at predetermined locations relative to the airbag mating members. Additionally, the base member of the retainer could be provided with apertures which are disposed at predetermined locations relative to the retainer mating members and which are arranged to align with the bag's apertures in the completed airbag/retainer subassembly. When the airbag mating members are mated with the retainer mating members, the apertures in the inflatable bag would be simultaneously aligned with the corresponding apertures in the retainer.
Furthermore, the reaction device could be provided with apertures which are arranged to align with the aligned apertures in the inflatable bag and the retainer when the airbag/retainer subassembly is positioned in the predetermined orientation. The fasteners could then be inserted through the aligned apertures of the inflatable bag, the retainer, and the reaction device so that these fasteners could be used to couple the airbag and the retainer to the reaction device. If the reaction device includes a cradle, the apertures in the reaction device would be simultaneously aligned with the aligned apertures of the inflatable bag and the retainer when the airbag/retainer subassembly is engaged with the cradle.
Thus, an airbag/retainer subassembly according to the present invention comprises an airbag and a retainer which are joined together by airbag mating members and complementary retainer mating members. As was indicated above, the airbag mating members may be part of a mating device. Such a mating device preferably comprises a ring-shaped base member which is incorporated into the mouth of the inflatable bag and which is formed in one piece with the airbag mating members. More preferably, the mating device consists essentially of a one-piece molded plastic article and, even more preferably, the one-piece molded plastic article is made of nylon.
In an airbag assembly according to the present invention, the airbag/retainer subassembly is coupled to a reaction device. If the reaction device includes a cradle, this cradle engages the airbag/retainer subassembly and supports the airbag/retainer subassembly in the predetermined orientation. If the relevant coupling components constitute apertures, the airbag/retainer subassembly is coupled to the reaction device by suitable fasteners, such as rivets, which are inserted through the aligned apertures of the inflatable bag, the base member of the retainer, and the reaction device.